The tools so far have been using the strerror_r() GNU variant, that
returns a string, be it the buffer passed or something else.
But that, besides being tricky in cases where we expect that the
function using strerror_r() returns the error formatted in a provided
buffer (we have to check if it returned something else and copy that
instead), breaks the build on systems not using glibc, like Alpine
Linux, where musl libc is used.
So, introduce yet another wrapper, str_error_r(), that has the GNU
interface, but uses the portable XSI variant of strerror_r(), so that
users rest asured that the provided buffer is used and it is what is
returned.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Commit f6edb53c49 converted the probe to
a CPU wide event first (pid == -1). For kernels that do not support
the PERF_FLAG_FD_CLOEXEC flag the probe fails with EINVAL. Since this
errno is not handled pid is not reset to 0 and the subsequent use of
pid = -1 as an argument brings in an additional failure path if
perf_event_paranoid > 0:
$ perf record -- sleep 1
perf_event_open(..., 0) failed unexpectedly with error 13 (Permission denied)
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.007 MB /tmp/perf.data (11 samples) ]
Also, ensure the fd of the confirmation check is closed and comment why
pid = -1 is used.
Needs to go to 3.18 stable tree as well.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Based-on-patch-by: David Ahern <david.ahern@oracle.com>
Acked-by: David Ahern <david.ahern@oracle.com>
Cc: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/54EC610C.8000403@intel.com
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When doing a system-wide trace with Intel PT, the jump label set up as a
result of probing CLOEXEC gets reset while the trace is running. That
causes an Intel PT decoding error because the object code (obtained from
/proc/kcore) does not match the running code at that point. While we
can't expect there never to be jump label changes, we can avoid cases
that the perf tool itself creates.
The problem is avoided by first trying a cpu-wide event (pid = -1) for
probing the PERF_FLAG_FD_CLOEXEC flag and falling back to an event for
the current process (pid = 0).
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1407855871-15024-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Showing better error message in case we fail to open counters due to the
EBUSY error. If we detect oprofile daemon process running, we now
display following message for EBUSY error:
$ perf record ls
Error:
The PMU counters are busy/taken by another profiler.
We found oprofile daemon running, please stop it and try again.
In case oprofiled was not detected the current error message stays:
$ perf record ls
Error:
The sys_perf_event_open() syscall returned with 16 (Device or resource busy) for event (cycles).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?
Also changing PERF_FLAG_FD_CLOEXEC detection code not to display error
in case of EBUSY error, as it currently does:
$ perf record ls
Error:
perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error 16 (Device or resource busy)
perf_event_open(..., 0) failed unexpectedly with error 16 (Device or resource busy)
The PMU counters are busy/taken by another profiler.
We found oprofile daemon running, please stop it and try again.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: William Cohen <wcohen@redhat.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Link: http://lkml.kernel.org/r/1406908014-8312-1-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
